Keeping Things in Perspective: Weather vs. Climate in Operational Decision Making
As I write this, we are on the heels of catastrophic flooding in Houston due to Hurricane Harvey, and another major storm, Hurricane Irma, is churning its way through Florida and raising fears throughout the southeastern states.
The floodwaters have not fully receded and already we are hearing debate among scientists regarding how (if at all) Harvey’s intensity was influenced by climate based on a hypothesis (also debated) that extreme weather events become more frequent in a warmer world. The rhetoric reminds me of how often I see stories of the latest scientific studies projecting how climate change will impact our global agricultural production, and the message is often negative. However, these projections are fraught with uncertainty, based on atmospheric models that have yet to prove skillful in retrospectively simulating climate. My intent in this column is not to inflame the climate change debate, but simply to put a few things in perspective for everyone involved in agricultural production.
First, let’s review the difference between weather and climate, as I often hear these terms used interchangeably. Weather is defined as the actual individual values and events that occur or are expected to occur. Climate refers to typical conditions as represented through statistical analysis (averages, variability, extremes) of aggregated weather conditions spanning multiple years or decades (typically 30 years, but more or less can be used). Thus, climate is a signal buried in the noise of the actual weather.
An analogy might be the stock market, where daily individual stock prices are like the weather, and the long-term market indices are like the climate. Both the climate and market indices vary with time, sometimes with short-term trends and sometimes long-term identifiable trends, depending on the sample size and period of record. Attributing one event to a changing climate is like attributing the performance of one random company’s stock performance yesterday using the average Dow Jones Industrial Index over the last 10 years. But, it is the actual stock price that impacts the shareholders of that company, not the market indices, and that stock price most likely is driven by actions within or around the company, completely unrelated to the market index. On a daily basis, it is in the noise where we make decisions that have the highest impact on our livelihoods.
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Regardless of where one falls in the debate, even the Intergovernmental Panel on Climate Change (IPCC) recognizes that we cannot readily attribute any single weather event such as a hurricane to climate change. We have observed several major hurricanes in the relatively short recorded history of hurricane strikes in the U.S. (about 170 years of data, within which only the last 40 years or so have had the benefit of satellite imagery). In fact, on the all-time list of U.S. land-falling hurricanes, Harvey ranked 14th in overall intensity. In 1900, when atmospheric CO2 concentrations were still within the natural range, a hurricane considered by many to be the worst ever to hit the U.S. struck Galveston, destroying much of the city and killing somewhere between 9,000 and 12,000 people. And while Harvey did set a record for rainfall at 51 inches, two other storms, Amelia (1978) and Claudette (1979) dropped 48 and 45 inches, respectively, on the state of Texas.
This is not the first major flood event for that region nor will it be the last. Whether or not such a storm would statistically be expected to occur every 1,000, 500, or 100 years, there is still a chance that one will occur in any given year. The key is to be weather-resilient. That resiliency by and large is not affected by climate change in a practical sense. As a practical example, if I tell you with full certainty that your likelihood of a destructive hail event occurring on your field for the growing season has increased from 5% to 7%, how would your operations change? I suspect not one bit.
For the sake of argument, even if the climate projections are correct, most of the impact studies assume a steady state in technology, including those done around agriculture. However, what we know is that agtech, whether it be in farming practices, equipment advances, crop protection and nutrients, or plant genetics, has advanced rapidly and continues to do so at a much greater pace than our climate is changing, and none of those are considered in the studies I have seen outside of a passing comment. We have a remarkable ability to adapt to change, and our ability to protect our crops and increase yields and efficiency will likely more than compensate for any long-term regional changes for the vast majority of producers worldwide.
While we should be concerned about our air and water quality and make good decisions about our practices for the benefit of society, I believe the largest opportunity for more efficient farming lie in the ability to leverage our ever-increasing accuracy of near-term weather forecasting, where confidence is much higher in the outcomes and real, high-impact decisions can be made.
Good weather forecasts with enough lead time to prepare are critical. “Betting the farm” on long-range weather forecasts or climate change outlooks are very high-risk with little real-world practical application because of the scientific limitations. But we can make good decisions to plant optimally, improve our water management, apply chemicals responsibly, and harvest efficiently through quality weather forecast services combined with connected farm technology.